This invention relates to a method of resetting a system and more particularly to a reset circuit for automatically clearing unnecessary memory contents of an information processing system independently of the variations in the power source voltage when the power is switched on.
In general, changes in light intensity cause significant variations in the power source voltage of an information processing system such as a calculator powered by a solar cell and this frequently results in a runaway situation in the arithmetic system. A conventional method of meeting this situation was to provide a hardware reset key for the entire system which can be used in the case of a runaway. Incorporation of such a key, however, complicates the operations and reduces the number of keys that can be more effectively used. It is therefore desirable to be dispensed with such a reset key.
It is therefore an object of this invention to eliminate from an electronic apparatus the disadvantages of hardware reset keys described above.
It is another object of this invention to provide a method of automatically resetting a system by making use of the infinite operation time of a runaway to make a comparison with the normal operation time of its arithmetic system and to detect a runaway.
It is a further object of this invention to provide an information processing system containing a reset circuit which is capable of reliably and automatically clearing the contents of all memory elements of the system independently of the variations in the power source voltage when the power is switched on, and hence is suitable in an integrated circuit design.